Lubricants and/or other friction modifying materials are commonly applied to the rails of railroad tracks. The application of lubricant to the rails has been found to reduce the frictional wear on the railhead and the noise produced by the flanges of the wheels on the railhead. Lubricating devices that are positioned next to the rails of a railroad track and activated by the passage of the wheels of the railroad vehicle to discharge a lubricant onto the railhead are well-known. Many of the known lubricating devices include a lubricant supply tank located in the ground near the rail, one or more lubricant distributing elements positioned on one side of the rail, a pump in the supply tank for conveying lubricant through one or more pipes to the lubricant distributing elements positioned on one side of the rail, and an actuator element located along the length of the rail. The actuator element is suitably connected to the pump and operates the pump in response to the passage of the wheels of the railroad vehicle over the actuator element.
In some of the present-day lubricating devices, the connection between the actuator element and the pump in the supply tank is mechanical, involving an elongated rotatable drive rod with attendant joints, springs, bearings, etc. However, over time, these mechanical elements deteriorate due to wear and tear. Additionally, in order to function, these lubricating devices must be located above the ground next to the rail. The location of these devices generally results in damage to the devices particularly when the railroad vehicle derails or when rail equipment is dragged along the tracks. From this, it can easily be appreciated that a lubricating device using a mechanical connection is sometimes undesirable.
Further known lubricating devices include a connection between the actuator element and the pump in the supply tank that consists of either a single hydraulic fluid line or a recirculating fluid loop in which hydraulic fluid, such as light oil is caused to flow by the activation of the actuator element.
Electric lubrication systems can be used to supply lubricant to railroad tracks. In one known electric lubricating system, a fixed, standing cabinet is divided into two compartments. A lower compartment houses two containers of grease, one in use and the other in reserve. The upper compartment houses the electric motor driven pump and an electronic control box. The pump is arranged so that the pump inlet tube projects downward through the cabinet partition into the grease container below. Space is provided for the mounting of batteries and any additional electric regulator equipment for a DC version operated using batteries and/or solar panels. Initiation of pump operation is triggered from a vibration sensor mounted on a track sleeper and the pump action causes grease to be pumped via flexible hoses to grease distribution units adjacent the rail.
In the arrangements described above, the distribution of grease is triggered by the passing of a train, either by the mechanical depression of pumps by successive passing of wheels in the case of a mechanical lubricator or by the triggering of a sensor in the case of an electrical lubricator. Both systems are relatively inflexible and not adapted to all types and densities of traffic. For example, it might be the case that at one location, a mechanical lubricator might apply too much grease if a train having a large number of cars were to pass. On the other hand, in the case of a sensor-triggered lubricator which would not recognize the length of a passing train, too little grease might be applied.
There is, therefore, a need for an improved lubricating and/or friction modifying system, so that desired friction characteristics can be maintained.